Not Good for Crops

A worrisome forecast for the world's crops
Studies on rising ozone pollution, shorter winters, and an expanding tropical belt do not bode well for agriculture.

By Robert C. Cowen
If you are concerned mainly with temperature when you think about climate change, your perspective is too narrow.

Think also about other atmospheric changes such as rising ozone pollution. A recent study indicates that its increasing harmful effect on plants could cut the global economic value of crop production by 10 to 12 percent by this century's end. The research projects that regions such as the United States, China, and Europe would become net food importers.

Think, too, of how plants respond to a warmer environment. New research shows that a longer growing season is not always beneficial. Or consider new evidence that the tropical zone already is expanding faster than computer-based climate simulations have forecast.

These examples from the latest research make the point that ecologists trying to anticipate global change still have a lot to learn.

The new ozone projection was a shocker even for the Massachusetts Institute of Technology researchers who conducted it. The study projects that growing worldwide fossil fuel burning will boost global average ozone concentrations 50 percent by 2100 unless emissions are seriously restricted.